Detergent foam control agents

Abstract

Particulate foam control agents for powder detergents consist of 1 part by weight of silicone antifoam, not less than 0.3 part by weight of a water insoluble fatty acid or a fatty alcohol with 12 to 20 carbon atoms and a melting point in the range 45 to 80% or a monoester of glycerol and a fatty acid and a native starch carrier material. They give improved storage stability and require less organic material than the prior art agents.

That which is claimed is: 
     
       1. A particulate foam control agent in finely divided form for inclusion in a detergent composition in powder form, the agent consisting essentially of A. 1 part by weight of silicone antifoam,   B. not less than 0.3 part by weight of an organic material, said organic material being selected from (1) at least one fatty acid having a carbon chain containing from 12 to 20 carbon atoms, said organic material having a melting point in the range 45° to 80° C. and being insoluble in water   (2) at least one fatty alcohol, having a carbon chain containing from 12 to 20 carbon atoms, said organic material having a melting point in the range 45° to 80° C. and being insoluble in water   (3) a mixture of at least one fatty acid and one fatty alcohol, each having a carbon chain containing from 12 to 20 carbon atoms, said organic material having a melting point in the range 45° to 80° C. and being insoluble in water,   (4) an organic material having a melting point in the range 50° to 85° C. and comprising a monoester of glycerol and a fatty acid having a carbon chain containing from 12 to 20 carbon atoms, and     C. a native starch carrier material onto which the silicone antifoam and the organic material are deposited.   
     
     
       2. A particulate foam control agent according to claim 1 wherein silicone antifoam (A) comprises a polydimethylsiloxane having trimethylsilyl end-blocking units and having a viscosity at 25° C. of from 5×10 -5  m 2  /s to 0.1 m 2  /s. 
     
     
       3. A particulate foam control agent according to claim 1 wherein the silicone antifoam (A) comprises a silica with an average particle size of from 1 to 20μ, a surface area of at least 50 m 2  /g, and whereof the surface has been rendered hydrophobic. 
     
     
       4. A particulate foam control agent according to claim 2 wherein the silicone antifoam (A) comprises a silica with an average particle size of from 1 to 20μ, a surface area of at least 50 m 2  /g, and whereof the surface has been rendered hydrophobic. 
     
     
       5. A particulate foam control agent according to claim 1 wherein the organic material (B) is selected from materials which comprise stearic acid, materials which comprise stearyl alcohol and materials which comprise glyceryl monostearate. 
     
     
       6. A particulate foam control agent according to claim 1 wherein the weight ratio of organic material (B) to silicone antifoam (A) is in the range 0.7:1 to 1.5:1. 
     
     
       7. A particulate foam control agent according to claim 5 wherein the weight ratio of organic material (B) to silicone antifoam (A) is in the range 0.7:1 to 1.5:1. 
     
     
       8. A particulate foam control agent according to claim 1 wherein the amount of native starch used makes up from 40 to 90% by weight of the total foam control agent. 
     
     
       9. A particulate foam control agent according to claim 5 wherein the amount of native starch used makes up from 40 to 90% by weight of the total foam control agent. 
     
     
       10. A particulate foam control agent according to claim 6 wherein the amount of native starch used makes up from 40 to 90% by weight of the total foam control agent. 
     
     
       11. A particulate foam control agent according to claim 1 wherein the amount of native starch used makes up from 60 to 80% by weight of the total foam control agent. 
     
     
       12. A particulate foam control agent according to claim 5 wherein the amount of native starch used makes up from 60 to 80% by weight of the total foam control agent. 
     
     
       13. A particulate foam control agent according to claim 6 wherein the amount of native starch used makes up from 60 to 80% by weight of the total foam control agent. 
     
     
       14. A method of making a particulate foam control agent in finely divided form for inclusion in a detergent composition in powder form characterised in that 1 part by weight of silicone antifoam and not less than 0.3 part by weight of an organic material which is selected from (1) at least one fatty acid having a carbon chain containing from 12 to 20 carbon atoms, said organic material having a melting point in the range 45° to 80° C. and being insoluble in water   (2) at least one fatty alcohol, having a carbon chain containing from 12 to 20 carbon atoms, said organic material having a melting point in the range 45° to 80° C. and being insoluble in water   (3) a mixture of at least one fatty acid and one fatty alcohol, each having a carbon chain containing from 12 to 20 carbon atoms, said organic material having a melting point in the range 45° to 80° C. and being insoluble in water,   (4) an organic material having a melting point in the range 50° to 85° C. and comprising a monoester of glycerol and a fatty acid having a carbon chain containing from 12 to 20 carbon atoms, are contacted together in their liquid phase and are caused to be deposited onto native starch in admixture.   
     
     
       15. In a powder detergent composition comprising a detergent component and a particulate foam control agent, the improvement comprising using as the particulate foam control agent the composition of claim 1. 
     
     
       16. In a powder detergent composition comprising a detergent component and a particulate foam control agent, the improvement comprising using as the particulate foam control agent the composition of claim 5. 
     
     
       17. In a powder detergent composition comprising a detergent component and a particulate foam control agent, the improvement comprising using as the particulate foam control agent the composition of claim 6. 
     
     
       18. In a powder detergent composition comprising a detergent component and a particulate foam control agent, the improvement comprising using as the particulate foam control agent the composition of claim 8. 
     
     
       19. In a powder detergent composition comprising a detergent component and a particulate foam control agent, the improvement comprising using as the particulate foam control agent the composition of claim 11.